USB MUX Click

How does it work?

USB MUX Click is based on the TS3USB30E, a USB 2.0 1:2 multiplexer/demultiplexer switch with a single enable from Texas Instruments. It is an ESD-protected device capable of bidirectional switching of high-speed USB 2.0 signals while offering little or no attenuation of the high-speed signals at the outputs. Besides the ESD protection, the TS3USB30E offers a low bit-to-bit skew and high channel-to-channel noise isolation. Also, besides USB 2.0, it is compatible with USB 1.1 standard. The maximum speed the TS3USB30E is capable of is 480Mbps at USB 2.0.

USB MUX Click communicates with the host MCU using a few GPIOs. The OE bus-switch enable pin allows users to isolate the bus when not in use and consume less current. With a LOW logic level set on the OE pin, you can use it in combination with the SEL pin to select one of two USB signal paths and connect it to a common USB signal path, with a LOW logic level to a USB1 and a HIGH logic level to a USB2. The USB1 is set by default over the pull-down resistors R5 and R6, which puts both OE and SEL lines in a low logic state. In addition, the VBUS LED will indicate if the powered USB device is connected to the USB MUX Click.

This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

Specifications

Pinout diagram

This table shows how the pinout on USB MUX Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	SEL	Input Selection
Device Enable	OE	2	RST	INT	15	NC
ID COMM	CS	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	NC
	NC	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

USB MUX Click electrical specifications

Software Support

We provide a library for the USB MUX Click as well as a demo application (example), developed using MIKROE compilers. The demo can run on all the main MIKROE development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for USB MUX Click driver.

Key functions

• usbmux_set_oe_pin USB MUX set OE pin output function.

• usbmux_enable_output USB MUX enable output function.

• usbmux_set_output USB MUX select output function.

Example Description

This example demonstrates the use of the USB MUX Click. This driver provides functions for device configurations and for the selection of the output.

void application_task ( void )  
 { 
     static char index; 

     if ( 1 == log_read( &logger, &index, 1 ) )  
     { 
         switch ( index ) 
         { 
             case ( '0' ): 
             { 
                 log_printf( &logger, " Turning output off. rn" ); 
                 usbmux_disable_output( &usbmux ); 
                 break; 
             } 
             case ( '1' ): 
             { 
                 log_printf( &logger, " USB1 Enabled and selected. rn" ); 
                 usbmux_set_output( &usbmux, USBMUX_USB1_SELECT ); 
                 usbmux_enable_output( &usbmux ); 
                 break; 
             } 
             case ( '2' ): 
             { 
                 log_printf( &logger, " USB2 Enabled and selected. rn" ); 
                 usbmux_set_output( &usbmux, USBMUX_USB2_SELECT ); 
                 usbmux_enable_output( &usbmux ); 
                 break; 
             } 
             default: 
             { 
                 display_selection( ); 
             } 
         } 
     } 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.USBMUX

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MIKROE Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.